Linux config options to support i.MX6Solo and i.MX6DualLite SoC

I would like to strip down as much as possible my configuration file for a single Linux kernel image that will be used on boards with the two mentioned SoCs.

The main question is:

Which SoC options are the bare minimum that I need to enable to fully support both i.MX6Solo and i.MX6DualLite SoCs?

The kernel version I am working with is 4.9-1.0.x-imx.

The problem is that I am not able to compile the v4.9 kernel with my current configuration that worked for 4.1-2.0.x-imx.

Two main different configs I tried:

1. With almost all IMX SoCs enabled (used with my current 4.1-2.0.x-imx kernel)

## Cortex-A platforms#CONFIG_SOC_IMX5=yCONFIG_SOC_IMX50=y# CONFIG_SOC_IMX51 is not setCONFIG_SOC_IMX53=yCONFIG_SOC_IMX6=yCONFIG_SOC_IMX6Q=yCONFIG_SOC_IMX6SL=yCONFIG_SOC_IMX6SX=yCONFIG_SOC_IMX6UL=yCONFIG_SOC_IMX6ULL=yCONFIG_SOC_IMX7=yCONFIG_SOC_IMX7D=y# CONFIG_SOC_LS1021A is not set

## Cortex-A/Cortex-M asymmetric multiprocessing platforms#CONFIG_SOC_IMX6SLL=y# CONFIG_SOC_IMX7ULP is not setCONFIG_SOC_VF610=yCONFIG_VF_USE_ARM_GLOBAL_TIMER=y# CONFIG_VF_USE_PIT_TIMER is not set# CONFIG_ARCH_MEDIATEK is not set

2. Only IMX6Q/DL and IMX6SL option enabled

## Cortex-A platforms## CONFIG_SOC_IMX50 is not set# CONFIG_SOC_IMX51 is not set# CONFIG_SOC_IMX53 is not setCONFIG_SOC_IMX6=yCONFIG_SOC_IMX6Q=yCONFIG_SOC_IMX6SL=y# CONFIG_SOC_IMX6SX is not set# CONFIG_SOC_IMX6UL is not set# CONFIG_SOC_IMX6ULL is not set# CONFIG_SOC_IMX7D is not set# CONFIG_SOC_LS1021A is not set

## Cortex-A/Cortex-M asymmetric multiprocessing platforms## CONFIG_SOC_IMX6SLL is not set# CONFIG_SOC_IMX7ULP is not set# CONFIG_SOC_VF610 is not set# CONFIG_ARCH_MEDIATEK is not set

This is because CONFIG_HAVE_IMX_MU is now not defined and CONFIG_HAVE_IMX_RPMSG was selected in my config. The issue is that HAVE_IMX_MU option is selected only when SOC_IMX6SX or SOC_IMX7 is selected but HAVE_IMX_RPMSG does not have this dependency check.

Manually disabling CONFIG_HAVE_IMX_RPMSG solved that but I think it should be done automagically in Kconfig.

As well as the error with the CONFIG_SOC_IMX6SLL and imx6sll_lpddr2_freq_change function.